Exhaust treatment device with air compressor regulator



W. W. GARY May 15, 1962 EXHAUST TREATMENT DEVICE WITH AIR COMPRESSORREGULATOR Filed Nov. 25, 1960 3 Sheets-Sheet 1 INVENTQR. VVQ/GHT W:6/727 M A TrQEA/Em.

May 15, 1962 w. w. GARY 3,034,290

EXHAUST TREATMENT DEVICE WITH AIR COMPRESSOR REGULATOR Filed Nov. 25,1960 3 Sheets-Sheet 2 INVENTOR.

BY /me/ 147- TOE/VEYS.

May 15, 1962 w. w. GARY 3,

EXHAUST TREATMENT DEVICE WITH AIR COMPRESSOR REGULATOR Filed Nov. 25,1960 3 Sheets-Sheet 5 VENTOR u lem" 642 M m, 5 E

3,034,290 EEIAUST TREA'IWNT DEVICE Wl'l'ii AIR COMPRESSOR REGULATORWright Wesley Gary, 2317 Kimbridge Road, Beverly Hills, Calif. FiledNov. 25, 1960, Ser. No. 71,473 12 Claims. (Cl. 60-30) The presentinvention relates to air compressors or pumps, and it relatesparticularly to a novel compressorregulator combination adapted tofurnish fresh air to the exhaust system of an internal combustion engineto promote oxidation of unburned hydrocarbon and carbon monoxide exhaustcomponents in anti-smog apparatus associated with the exhaust system.

Exhaust gases from internal combustion engines, and particularly fromautomobile engines, contain some unburned hydrocarbons which accumulatein the atmosphere and react to sunlight to form smog which causes eyeirritation, is harmful to agricultural production, and appears to be asubstantial human health hazard. Such exhaust gases also include carbonmonoxide which, although not appearing to be a smog producing agent, isa poisonous gas and as such constitutes a considerable health hazard. Agreat deal of effort has been expended in recent years in thedevelopment of anti-smog apparatus. One form of such apparatus is theafterburner for direct burning of the undesired materials attemperatures above 2000" F. Another form is the catalytic converter forcatalytically oxidizing or burning the. unwanted materials attemperatures above about 500 F. In my copending ap plication Serial No.27,721, filed May 9, 1960 for Catalytic Converter System for InternalCombustion Engines 1 have illustrated, described and claimed apparatusfor oxidizing the unburned hydrocarbon and carbon monoxide components ofthe engine exhaust by a novel combination of direct ignition burning andcatalytic oxidation, which I have found to provide much more efficientoxdation of these unwanted exhaust components over the entire range ofengine operating conditions than either an afterburner or a catalyticconverter used alone.

Regardless of the type of apparatus employed for oxidizing thehydrocarbon and carbon monoxide components of the engine exhaust,whether it be an afterburner, a catalytic converter or apparatus suchas'that described in my said copending application Serial No. 27,- 721involving both direct ignition burning and catalytic oxidation, it isnecessary to introduce fresh air into the exhaust line upstreamof theoxidizing apparatus in order to support the combustion or oxidation ofthe unwanted exhaust components. I have found in practice that the mostpractical source of supply of fresh air for the exhaust system is an aircompressor or pump of the positive displacement type which is driven bythe engine fan belt. However, the air requirements for efficientoxidation of the unburned hydrocarbons and carbon monoxide in theexhaust system at relatively high speeds, as in freeway driving, areonly slightly greater than the requirements at engine idle speeds sothat the air compressor must include means for controlling thecompressor output rate to a relatively small increase upon relativelylarge increases in engine speed.

The following example illustrates some of the factors which must beconsidered in connection with the air supply source. This example isbased upon the use of a 235 cubic inch displacement engine, such as aChevrolet 6 cylinder engine, it being understood that more air would berequired for larger displacement engines. In the example, my catalyticconverter system set forth in my said copending application Serial No.27,721 is employed for oxidizing the unburned hydrocarbons and carbonmonox ide by combined direct ignition burning and catalytic oxidation.

In tests made with such equipment, at engine idle speeds of about 450r.p.m., my catalytic converter system has been found to require fromabout 1 /2 to 2 cubic feet of air per minute. At this time the amount ofexcess air which is added to the exhaust system is a relatively largepercentage of the exhaust volume, which is on the order of about 6 cubicfeet per minute.

However, when the automobile is in high speed operation, such as infreeway driving at about 65 miles per hour or more, the hydrocarbon andcarbon monoxide content of the exhaust is relatively low, so that theexcess air added to the exhaust need ,be only a very small percentage ofthe exhaust volume'to perform its function of oxidizing these smallpercentage components. In the present example, with the engine inproperly regulated condition, the amount of added air required is onlyfrom about 2 to 3 cubic feet per minute at high speeds. Under suchrelatively highspeed operation, the volume of exhaust gases may exceedcubic feet per minute. If quantities of air in excess of about 3 cubicfeet per minute are added, then the excess air serves no beneficialfunction of oxidizing unwanted exhaust components, but does have adetrimental efiect of cooling the catalytic converter.

At the time of high speed operation the exhaust gases, undiluted withcold .air, will reach 1200 F. to 1300" F. temperature, and with about 2cubic feet per minute of injected air will be quenched to about 1150 F.Larger amounts of air would reduce the temperature proportionally. Atthe time of this high speed operation, it is not important that thetemperature be abnormally high because hydrocarbon and carbon monoxidecontents are down close to acceptable quantities. However, if at suchtime air is added to the exhaust stream to give a temperature of about850 F. to 900 F., then when deceleration, idle or heavy accelerationfollows, and hydrocarbon and carbon monoxide quantities are accordinglyboth raised to a relatively high level, the catalyst temperature in thecatalytic converter (particularly if the converter has been used on theroad for an extended period) would be too low to spontaneously ignitethe carbon monoxide, which is actually the highest source of burningheat. Since the exhaust gases under deceleration or idle are down at atemperature of only about 400 F., the catalyst bed without the benefitof the burning carbon monoxide would then rapidly cool and the exhaustgases would not be properly treated.

This problem of providing only a relatively small increase in thecompressor output flow over a wide input speed range of the rotary powersource which drives the compressor is further complicated by largevariations in the exhaust pressure, and hence in the back pressure onthe compressor output, such back pressure not being a direct function ofthe engine speed. For example, in tests wherein one of my catalyticconverters was embodied in the exhaust system, where the automobile wasrunning on the level at 40 miles per hour the back pressure was onlyequivalent to about 10 inches of water, while when the car was climbinga grade at full throttle at 40 miles per hour the back pressure wasequivalent to about 60 inches of water, despite the fact that the enginespeed was approximately the same.

Prior attempts to limit the compressor output to within the relativelynarrow range required for efiicient oxidizing of the hydrocarbons andcarbon monoxide in the exhaust system have included slip-clutch drivesfor providing rotary power to the pump, and also pump output pressurebypass valve means for diventing the flow of excess air from the pump.However, heretofore such devices have not been capable of controllingthe output to within the required narrow range or of keeping the effectsof i .for the-pump.

. V '3 back pressure variations from causing substantial unwantedchangesin the amount of air provided by the compressor to the exhaust line. 7

in view of the foregoing and other problems in the art,

it is an object of the present invention to provide a novel aircompressor and means for regulating the output therefof whereinthe air,output rate will increase only a relatively small amount forlarelatively large increase in the speed of a rotary power source drivingthe pump.

Another object of the present invention is to provide anaircompressor-regulator combination which will not only have an output .airflow rate that increases within relatively narrow limits for relativelywide increases in "the speed of a rotary power source driving thecompressor, but which is also relatively immune from large varia- =tionsin back-pressure loading on the pump output.

- A further objectof the present invention is toprovide a novel air pumpand means for regulating the output thereof which have particularutility ;in combination with anti-smog apparatus associated with aninternal combustion-engine for oxidizing unburned hydrocarbon and car- I-It is'also an object of the present invention to provide outputregulating-means for' an air compressor of the "character describedwhich includes a regulator valve associated with the pump inlet andhaving a floating valve element that rests in a lowermost position atlow pump speeds permitting relatively free flow of inlet air to thepump, and which rises upon a predetermined inlet flow rate to anuppermost position Wherein the floating valve element provides arestricted inlet orifice which limits the a volume of air pumped uponfurther "increases in the [pump speed. a

Another object of the' -invention is to provide an air pump of thecharacter described having air flow regulating means associatedtherewith which combines an inlet "regulator valve having a floatingvalve element with a, slip-clutch drive connection between the internalcombustion engine and the pump shaft, the slip'clu-tch having a minimumof slippage at low engine speeds and 'considerfable slippage atrelatively high engine speeds, this combined regulating means beingeifective to limit the air outflow of the pump to within-a desirednarrow increase for large increases in engine speed, with a minimum ofeffect fromexhaust back pressure.

Further objects and advantagesof thiepresent invention will appearduring the course of'the following part of the specification wherein thedetails of construction and scribed reference to the accompanyingdrawings,,in

' no.2 looking "from 1m to right in FIG. 2.

'FIG. 4 is an end elevation View of theair pump looking from-right toleft in FIG. 2.

FIG. 5 is an'axial vertical section taken on the line, .55 in FIG. 4showing the internaldetails of construction of the pump. 1

, PEG. 6 is a cross-sectional view' taken on the line 6 -6 I of FIG. 5showing details of the slip-clutch assembly.

FIG. 7 is a cross-sectional view along th'eline'7-7 in l PEG. 5showing-detailsof the pump in'the region of the I pump cavity. a

FIG. :8 iso vertical section .illustratingithe details of constructionof my presently preferred regulator valve engine air filter 18 to thepump inlet.

Referring to the drawings, in FIG. 11 have illustrated air pump orcompressor 19 as operatively connected to a conventional internalcombustion engine 12, pump 10 being driven by the engine fan belt 14'.Although pump 10 is shown as heing'driven off of the inside of the fanbelt, it may be driven by either .the inside or the outside of the fanbelt, and may, if desired, be conveniently mounted on a vehiclegenerator which is likewise driven by the fan belt 14.

Fresh air is provided to the pump inlet port through an air inletconduit 16, which preferably extends from the Inlet conduit 16 may, ifdesired, comprise a plastic hose. By thus taking the fresh air from the.air filter, pump noise is substanhon-monoxide components of the engineexhaust, the compressor output being connected to the exhaust system'-to provide fresh air to assist in the oxidation.

tiaily eliminated and filtered air is fed to the pump unit. only a veryminor vacuum is caused by the air filter and the inlet conduit 16 sothat the fresh air provided to the pump is substantially at atmosphericpressure. The air check valve'may he provided immediately adjacent to or:as apart of the air pump it), and may comprise'a diaphragm of neoprene:or flexible plastic with a valve base or seat upstream of the diaphragmcomprising a part of the pump discharge port. The downstream side 'ofthis diaphragm is-connected to output conduit 22 at a properly shapedfitting which is easily removable for replacing-.orinspectingthe-conduit 22.

The pump output conduit 22 may, if desired, comprise copper tubing, aninternal diameterfor such tubing of about of an inch appearing to beadequate for this conduit. Alternatively, the output conduit '22 may beQ a FIG. l of the drawings illustrates the embodiment of air 7 mode ofoperation of a preferred embodiment are deat least partly composed ofplastic hose from the air pump 10 to a point closely approaching theentrance to exhaust pipe 24, with metal forming .the portion of outputconduit 22 immediately adjacent to the exhaust pipe. With thisconstruction, in :case of failure of lthfi check valve 28,'the plastichose will melt, and discharge any hot exhaust gases, thereby protectingboth the compressor and the check valve.

pump it) in connection with an internal combustion engine employing thecatalytic converter system shown, described and claimed in mysaidcopending application Serial No.

' 27,721. In this arrangement, catalytic case .36 is operativelyconn'ected to the exhaust pipe EAat the front end of case 39, with thedecontaminated exhaust gases pasS- ing out of the rearend of convertercase .30 and through tail pipe 32. Spark plug 34 is disposed in theexhaust line just ahead of .thecatalytic converter case 30 for directignition of theexhaust-air mixture prior to the catalytic oxidation inconverter case 36, this direct ignition not only accomplishing part ofthe oxidation of the unburned hydrocarbons and carbon monoxide intheexhaust stream,

hut-also heating .up the exhaust gases to a point where the catalyst inthe converter'case 36 will function most efficiently. The required highvoltage interrupted electricity for spark .plugfidisprovided by sparkcoil 36 through a suitable electrical conductor 38, the primary currentfor coil 36 being interrupted as required by suitable interrupter points49 which are preferably mounted on air-pump t0 ;air outputof pump 19which will restrict the increase in the air output of the pump to arelatively small amount for relatively large increases in engine speed,so :that the a air output of pump will closely match the airrequirements of the catalytic converter system. Thus, in the examplepreviously given, for engine idle speeds of about 450 r.p.m., theconverter system requires between about 1%. and 2 cubic feet of air perminute, While at highway speeds of the order of 65 miles per hour andabove, when the engine is rotating at about 2500 rpm. or faster, the airrequirement is only between about 2. and 3 cubic feet per minute (thesefigures being for a 235 cubic inch displacement engine such as aChevrolet 6 cylinder engine, with larger displacement engines requiringproportionally more air). In order to accomplish this desired regulationof the air output of pump 10, I have found it preferable to combine twocontrol devices with the air pump, namely, (1) the slip-clutch bestshown in FIGS. 5 and 6 of the drawings, and- (2) the regulator valvebest shown in FIGS. 2 and 8 of the drawings.

The slip-clutch drive employed in pump 19 has the desirablecharacteristic of greatly increased slippage with increases in enginespeed, thereby maintaining only a small increase in pump air output athigh speeds over that atlow speeds Also, this slip-clutch drive, bypermitting only a small amount of increase in the pump speed for .highengine speeds as compared with the'jpump speed e for low engine speeds,keepsthe pump operating within a speed range which involve a minimum'ofwear and tear in the pump, and will actually prevent rotor bladebreakage, pump speeds above 4980 rpm. usually hearing or broken blade,the slip-clutch will continue to run and the belt and pump pulley willfunction normally; where otherwise something must give away, which wouldresult in a burned-out belt or further damage to the pump.

It has been found in practice, however, that the slip drive for thepump, when adjusted so as to rotate the pump at a speed which will notcause blade breakage or undue wear, will produce pump air deliveriesranging from about 2 cubic feet per minute at engine idle speeds toabout 5 /2 cubic feet per minute at high speeds, which is somewhathigher than the air output for optimum catalytic converter operation. Ithas also been found that the slip drive is to some extent susceptible toexhaust pressure changes, increases in that pressure increasing the loadon the pump vanes, resulting in increased slippage in the drive.

By combining the regulator valve 20 in the pump unit, however, I havebeen able to control the output to the desired range of from about 1.5to 2 cubic feet per minute at idle to about 2 to 3 cubic feet per minuteat high speeds, and I have satisfactorily isolated the pump performancefrom variations in the back pressure.

Referring now to the specific details of construction of the pump, thepump 10 includes a suitable base member 42 upon which a pair of spacedend plates 44 and 46 are mounted by means of bolts 48 or other suitablemeans. A cylindrical pump case 50 is supported between end plates 44 and46 by screws 52 to provide a sealed pumping chamber therein.

Pump inlet port 54 is provided through end plate 46, and is operativelyconnected to regulator valve 20 through a tubular connector 56. Outletport 58 is likewise provided through end plate 46, and communicates withthe outlet conduit 22. I

It will be noted that by providing inlet and outlet ports 54 and 58,respectively, in the end wall rather than in the cylindrical pump caseas is the usual procedure, I

V greatly reduce frictional wear of the ports, and on the pumping vanes,as the ports are not in the area of centrifugally forced engagement ofthe vanes against the pump case. Y

Pump shaft 60 is rotatably mounted in sealed antifriction bearings 62which are supported in the respective end plates 44 and 46,

6 V and pump rotor 64 is keyed to shaft 60 within pump case 50 betweenend plates 44 and 46 so as to rotate with shaft 60. Pumping vanes 66 areradially slidably mounted in rotor 64 so as to be engaged in slidingcontact with the inner Wall of pump case 50 by centrifugal force.

The pump shaft 60 is driven through a circular clutch plate 68 that ismounted on a threaded spindle 70 on one end of pump shaft 60, plate 68being held in position by nut 72.

Clutch plate 68 is disposed Within a clutch housing 74 I which is drivenby the'engine fan belt 14, housing 74- including a pulley portion 76having an external annular recess '78 therein for receiving the fan belt14. Clutch housing portion 76 is rotatably mounted on an anti-frictionbearing 84) which is supported on a fixed hub 82 extending outwardlyfrom end plate 44 and which is retained on hub 82 by a suitableretaining ring 83. The pulley portion 76 is tapped in several locationsnear the periphery to accept screws which clamp and retain the remainderof clutch housing 74 to pulley portion 76.

' Clutch housing '74 also includes an intermediate housing member 84 anda housing cover member 66, the

cover member 86 preferably being finned for cooling purposes andincluding an axial cup or tbimble portion 88 having a grease reservoir90 therein. Upon rotation of the clutch housing 74, grease disposedtherein frictionally engages the clutch plate 68 so as to rotate clutchplate 68 and pump shaft 66. A combination of a proper grease in clutchhousing 74 and a clutch plate 68 of the particular construction shown inthe drawings and herecircularly arranged openings 92 therethrough,preferably six in number, the openings 2 preferably being spaced atequal radial distances from the center of'clutch plate 68. A channelrecess 94 extends from each opening 92 to the periphery of clutch plate68 on one side of clutch plate 68, the recesses 94 extending to a depthof approximately one-third the thickness of the clutch plate.Similar'channel recesses 96 on the other side of clutch plate 68 extendfrom the respective openings 92 to the periphery of the clutch plate.The channel 94 from each opening 92 will overlap the channel 96 from anadjacent 'opening 92, but the channels will not break out into each 68through the channels 94 and 96, utilizing the larger clearance betweenthe outer edge of clutch plate 68 and clutch housing 74 as a reservoirfor the grease in transit, limiting the tendency to increase frictionalengagement at this point during high speed operation. 7

A high temperature silicone grease has been found satisfactory for usein the clutch housing, providing an increase of from about 1 /2 to 2cubic feet per minute to about 5 cubic feet per minute of pump airoutput for an engine speed range of from about 450 r.p.m. (idle speed)to 2500 rpm. (highway speed), where the pump is operated without thebenefit of the regulator valve 241'.

- Variations in this relationship between pump air output have acharacteristic of thixotropy; that is, one which will functionprincipally as asolid until a certain shear] point is reached, andthereafter will function primarily as a liquid. Silica .which ispowdered to a fineness of lessthan 1 micron in particle size exercisesthis property 7 a when mixed with a suitable carrier liquid such aswater or oil. Other materials which will perform in this mannet arefinely powdered eantocel produced by Monsanto Chemical Company andfinely powdered Kaolirf produced by Minerals and Chemicals Corporation.

Finely powdered silica appears tob e preferred as it does' not 'attriteby grinding itself, Alsovery small concern ftrationsiof Guar, such asJaguar, a commercial gum resin, willQpromote thixotropy, so that smallquantities of such material'may be employed.

' Iffind it convenient to mount the interrupterpoints 40 on -the outsideof pump end plate 46, and toprovide a 'multi-lobed cam member 98 on theend of pump shaft 7 60 which projects outwardly through end plate 46 forproducing the vibratory motion required for the interrupter points 4dThe points '40 include a movable contact member 1th and a fixedcontactrmeflmber 1ti2,'the

mov able contact member 1% being spring-biased against esiredinterruption enabling the coil .to then step-up the primary voltage to asecondary voltage snfilcient to'fire the ignition spark plug 34+. Atypical installation would find fixed contact member 162 electricallygrounded to pump end plate .46, and movable contact member 100 insulatedfrom end plate 46 and connected externally to the primary coil winding.A capacitor may be used across interrupter points 40 if desired, bothfor the elimination of metal transfer andifor the moresatisfactoryoperation of the ignition system which includes the sparkplug 34. Referring to FIGS. 2 and 8 of the drawings, I will now describea presently preferred -.ernbodiment of the regulator valve whichcooperates with the slip-clutch drive to provide the desired air outputof the pump. 7

' The regulator valve includes a vertically arranged :tubular valvehousing 104 which is preferably supported on the pump casing as bymeans'of 'a supporting bracket i 106 that extendsaround valve. housing104 and is .at-

cached to pump end plate 46 by one or more screws 193. The regulatorvalve 20 includes a bottom end closure 110 which extends across thelower end oftubular valve housing 104, with valve inlet port 112extending through bottom end closure i110 and communicating with asuitable inlet fitting 1 14 attached to end closure 110. The air inletconduit 16'is operatively connected to inlet fitting 114 by conventionalmeans.

. .8 valve housing 104 through outlet port '122 and fitting '124, andthen will pass through tubular connector 56 to the pump inlet 'port. 54p A wall 126 extends across valve housing 164 below outlet port 122,'thewalli126 being provided with an orifice 128. An adjusting screw 135} isthreadedly mounted in top end closure 12d, extending downwardly throughvalve .orifice 128; By this means, when the air how increases beyond acertain minimum flow, it will blow the floating ball valve element 118upwardly until valve element 118 isstopped by the lower end of adjustingscrew 13%. The ball will remain in this'position so as :to

define a more restricted valve orifice until'the .air flow drops belowthe said predetermined minimum flow, at which time the ball will againfall down against the screen 116, removing the restriction from valveorifice 123.

In the example previously given, where the desired pump output rangedfrom about 1% to' 2 cubic feet per minute at idle engine speeds tobetween 2 and 3 cubic feet per-minute at highway speeds, the relativesizes of the ball valve element 118 and the tubular valve housing 104are preferably!suchfthatiwhen the input ,air flows at 2 cubic feet perniinute or less, the valve element 1-18 will rest on screen spacer.116;at the bottom of tubular -housing illa, butwhen the airflowrateincreases to in ,7 excess ofr2 cubic feet per minute, "the ballvalve element 118 will rise and be air-borne, seating againstthe bottomof adjusting screw 13 adjacent valve orifice 128. The

ill

Disposed across the inside of valve housing 14M above; "bottom endclosure 110 is ascreen spacer member 1 16 upon which a floating valve.element 118 normally rests.

Valve element 1181s preferably of the ball type, and is suitably smallerthan the inside .diameter of valve housing-104. The valve element .118is spaced sufiici ently above inlet port 112'by 'thewscreen 11 6 topermit incoming air to pass .freely tbroughvportyllz and around valveelement 11-8 upwardly through valve housing 104 when ball valve element118 is in its lowermost, rest position against screen 116. It will beapparent that other suitable spacer means may be provided in place ofthe "Atop end closure'member '120 completely closes off for attachmentof theoute're'rid of tubular connector 56, whereby valve outlet airwilllpass' out of the uppere of 1 screen 116, which is merely thepresently preferred means v for this purpose.

ball "valve element 118 will remain in this position until the air flowagain decreases to below about 2 cubic feet per minute, at which timethe ball will drop down against screen 116 and orifice 128 will beunrestricted.

I have found in practice that by properly adjusting the screw 130, theball valve element '118 can be positioned relative to orifice 128 so asto control the air flow to only slightly in excess of 3 cubic feet perminute at high engine speeds. The compressor at high speeds, in effect,isunder a partial vacuum or suction which variesv fromsubstantially'zero at 2 cubic feet per minute to higher vacuums as thespeed is increased. Back-pressure loading upon the compressor fromthe'engine appears .to have no .eltect upon the airdelivery of thecompressor ,to the exhaust system above 2 cubic feet .per minute, -assuch back pressure only afiectszthe degree of clutch slippage, which 2/2 cubic feet per minute air flow merely affects the amount of suctionat the pump inlet.

While the instant invention has been shown and described herein in whatis conceived to be the most practical and preferred embodiment, it isrecognized that departures may be made therefrom within the scope of theinvention, which is therefore not to be limited to the .detailsdisclosedherein, but is to be accorded the full scope of ,theclaims.

1. Apparatus for removing impurities from an internal combustion engineexhaust system which comprises: an exhaust conduit; means in saidexhaust conduit for oxidizing exhaust ingredients not previouslyoxidized .in the engine; and air injection'means connected to saidexhaust conduit for introducing air into said exhaust conduit to providea mixture of air and exhaust ingredients, said air injection meansincluding an air pump havinga housing with air .inlet and outlet ports,a rotor member rotatably mounted in the housing for drawing air inthrough said inlet port and pumpingthe air out through :said outletport, rotary power input'means rotatably mounted in the housing andconnected to ,the rotor for driving the rotor, and an airflow regulatorvalve connected to said pump inlet port, said regulator valve includinga body having a passage therein, an air inlet opening and anair outletorifice in the bodycommunicating with said passage, air conduit meansconnecting the orificeto the pump inletport, a valve element of smallerd a closed position adjacent to said orifice in which the valve elementpartially restricts the orifice, said valve element being normallybiased toward its said open position, whereby when the flow of pumpinput air through said valve is below a predetermined rate the valvewill be in its open position and the air will have relativelyunrestricted passage through the valve, and when the flow of pump inputair is above said predetermined rate the air will blow the valve elementto its said closed position at which the valve element will restrict theflow of air through the orifice.

2. Apparatus as defined in claim 1 wherein saidoxidiz ing means includesdirect ignition means in said exhaust conduit downstream of said airinjection means for igniting exhaust ingredients not previouslycompletely oxidized, and catalytic oxidizing means connected to saidexhaust conduit downstream of said direct ignition means for oxidizingexhaust ingredients not previously completely oxidized.

3. Apparatus as defined in claim 2 wherein said connection between saidrotary power input means and said rotor is a slip-clutch driveconnection.

4. Apparatus as defined in claim 3 wherein said rotary power input meanscomprises a clutch housing rotatably mounted on the pump housing, andsaid slip-clutch drive connection includes a clutch plate within saidclutch housing, said clutch plate being connected to the rotor so thatthe clutch plate and rotor rotate together; and thick fluid material inthe clutch housing for imparting rotation from the clutch housing to theclutch plate.

5. Apparatus as defined in claim 4 wherein said biasing is accomplishedby vertical arrangement of said passage with said inlet openingcommunicating with the passage below said orifice, the valve elementbeing urged by gravity toward its said open position.

6. Apparatus as defined in claim 5 wherein said valve element is a ballloosely disposed in said passage.

7. Apparatus as defined in claim 4 wherein said thick fluid has thecharacteristics of thixotropy.

8. Apparatus for removing impurities from an internal combustion engineexhaust system which comprises: an exhaust conduit; means in saidexhaust conduit for oxidizing exhaust ingredients not previouslyoxidized in the engine; and air injection means connected to saidexhaust conduit for introducing air into said exhaust conduit to providea mixture of air and exhaust ingredients, said air injection meansincluding an air pump having a housing with air inlet and outlet ports,a rotor member rotatably mounted in the housing for drawing air inthrough said inlet port and pumping air out through said outlet port,rotary power input means rotatably mounted in the housing and connectedto the rotor for driving the rotor, and an airflow regulator valveconnected to said pump inlet port, said regulator valve including abodyhaving a passage therein, an air inlet opening and an air outlet orificein the body communicating with said passage, said passage extendingupwardly from said inlet opening to said orifice, air conduit meansconnecting the orifice to the pump inlet port, a valve element ofsmaller cross-section than said passage disposed in said passage andmovable between a lowermost position spaced above said inlet opening andan uppermost position adjacent to said orifice in which the valveelement partially restricts the orifice, abutment means in said passageagainst which the valve element seats in its lowermost position, andstop means adjacent to said outlet orifice against which the valveelement seats in its uppermost position, whereby when the flow of pumpinput air through said valve is below a predetermined rate the valvewill be in its lowermost position and the air will have relativelyunrestricted passage through the valve, and when the flow of pump inputair is above a predetermined rate the air will blow the valve element toits uppermost position at which time the valve element will restrict theflow of air through the orifice.

9. Apparatus as defined in claim '8 wherein said abutment means is awire screen extending across said passage above said inlet opening.

10. Apparatus as defined in claim 6, wherein'said pasternal combustionengine exhaust system which cornprises: an exhaust conduit; means insaid exhaust conduit for oxidizing exhaust ingredients not previouslyoxidized in the engine; and airinjection means connected to said exhaustconduit for introducing air into said exhaust conduit to provide amixture of air and exhaust ingredients, said air injection meansincluding an air pump having-a housing with air inlet and outlet ports,a rotor member rotatably mounted in the housing for drawing air inthrough said inlet port and pumping air out through said outlet port,rotary power input means rotatably mounted in the housing; a slip-clutchdrive connection in the pump between said power input member and therotor, and an airflow regulator valve connected to said pump forregulating the rate of flow of air pumped through said outlet port, saidregulator valve including a body having a pas sage therein, an air inletopening and an air outlet orifice in the body communicating with saidpassage, air conduit means connecting the orifice to the pump inletport, a

valve element of smaller cross-section than said passage disposed insaid passage between said inlet opening and said orifice, and movablebetween an open position spaced from said orifice and a closed positionadjacent to-said orifice in which the valve element partially restrictsthe orifice, said valve element being normally biased toward its openposition, whereby when the flow of pump input air through said valve isbelow a predetermined rate the valve will be in its open position andthe air will have relatively unrestricted passage through the valve, andwhen the flow of pump input air is above said predetermined rate the airwill blow the valve element to its said closed position at which timethe valve element will restrict the flow of air through the orifice.

References Cited in the file of this patent UNITED STATES PATENTS

1. APPARATUS FOR REMOVING IMPURITIES FROM AN INTERNAL COMBINATION ENGINEEXHAUST SYSTEM WHICH COMPRISES: AN EXHAUST CONDUIT; MEANS IN SAIDEXHAUST CONDUIT FOR OXIDIZING EXHAUST INGREDIENTS NOT PREVIOUSLYOXIDIZED IN THE ENGINE; AND AIR INJECTION MEANS CONNECTED TO SAIDEXHUSTED CONDUIT FOR INTRODUCING AIR INTO SAID EXHAUST CONDUIT TOPROVIDE A MIXTURE OF AIR AND EXHUSTED INGREDIENTS, SAID AIR INJECTIONSMEANS INCLUDING AN AIR PUMP HAVING A HOUSING WITH AIR INLET AND OUTLETPORTS, A ROTOR MEMBER ROTATABLY MOUNTED IN THE HOUSING FOR DRAWING AIRIN THROUGH SAID INLET PORT AND PUMPING THE AIR OUT THROUGH SAID OUTLETPORT, ROTARY POWER INPUT MEANS ROTABABLY MOUNTED IN THE HOUSING ANDCONNECTED TO THE ROTOR FOR DRIVING THE ROTOR, AND AN AIRFLOW REGULATORVALVE CONNECTED TO SAID PUMP INLET PORT, SAID REGULATOR VALVE INCLUDINGA BODY HAVING A PASSAGE THERIN, AN AIR INLET OPENING AND AN AIR ORIFICEIN THE BODY COMMUNICATING WITH SAID PASSAGE, AIR CONDUIT MEANSCONNECTING THE ORIFICE TO THE PUMP INLET PORT, A VALVE ELEMENT OFSMALLER CROSS-SECTION THAN SAID PASSAGE DISPOSED IN SAID PASSAGE BETWEENSAID INLET OPENING AND SAID ORIFICE, AND MOVABLE BETWEEN AN OPENPOSITION SPACED FROM SAID ORIFICE AND A CLOSED POSITION ADJACENT TO SAIDORIFICE IN WHICH THE VALVE ELEMENT PARTIALLY RESTRICTS THE ORIFICE, ANDSAID VALVE ELEMENT BEING NORMALLY BIASED TOWARDS ITS SAID OPEN POSITIONWHEREBY WHEN THE FLOW OF PUMP INPUT AIR THROUGH SAID VALVE IS BELOW APREDETERMINED RATE THE VALVE WILL BE IN ITS OPEN POSITION AND THE AIRWILL HAVE RELATIVELY UNRESTRICTED PASSAGE THROUGH THE VALVE, AND WHENTHE FLOW OF PUMP INPUT AIR IS ABOVE SAID PREDETERMINED RATE THE AIR WILLBLOW THE VALVE ELEMENT TO ITS SAID CLOSED POSISTION AT WHICH THE VALVEELEMENT WILL RESITRICT THE FLOW OF AIR THROUGH THE ORIFICE.